using System;
namespace SwappingWithTemp
{
class Program
{
static void Main(string[] args)
{
int x = 10, y = 20;
int temp = x;
x = y;
y = temp;
Console.WriteLine("After swapping:");
Console.WriteLine("x = " + x);
Console.WriteLine("y = " + y);
Console.ReadLine();
}
}
}
✅ 2. Swap Two Numbers (Without Temp Variable)
OUTPUT
After swapping:
a = 10
b = 5
✅ 3. Reverse a String
using System;
namespace ReverseString
{
class Program
{
static void Main(string[] args)
{
string input = "hello";
char[] charArray = input.ToCharArray();
Array.Reverse(charArray);
string reversed = new string(charArray);
Console.WriteLine("Reversed string: " + reversed);
Console.ReadLine();
}
}
}
✅ 4. Check for Palindrome
using System;
namespace PalindromeCheck
{
class Program
{
static void Main(string[] args)
{
string input = "madam";
string reversed = new string(input.Reverse().ToArray());
if (input == reversed)
Console.WriteLine("Palindrome");
else
Console.WriteLine("Not Palindrome");
Console.ReadLine();
}
}
}
✅ 5. Fibonacci Series
using System;
namespace FibonacciSeries
{
class Program
{
static void Main(string[] args)
{
int n = 10, a = 0, b = 1;
Console.WriteLine("Fibonacci Series:");
for (int i = 0; i < n; i++)
{
Console.Write(a + " ");
int temp = a;
a = b;
b = temp + b;
}
Console.ReadLine();
}
}
}
✅ 6. Factorial of a Number
using System;
namespace FactorialProgram
{
class Program
{
static void Main(string[] args)
{
int num = 5, fact = 1;
for (int i = 1; i <= num; i++)
{
fact *= i;
}
Console.WriteLine("Factorial of " + num + " is: " + fact);
Console.ReadLine();
}
}
}
✅ 7. Prime Number Check
using System;
namespace PrimeCheck
{
class Program
{
static void Main(string[] args)
{
int num = 17, flag = 0;
for (int i = 2; i <= Math.Sqrt(num); i++)
{
if (num % i == 0)
{
flag = 1;
break;
}
}
if (flag == 0)
Console.WriteLine(num + " is Prime");
else
Console.WriteLine(num + " is Not Prime");
Console.ReadLine();
}
}
}
✅ 8. Sum of Digits
using System;
namespace SumOfDigits
{
class Program
{
static void Main(string[] args)
{
int num = 123, sum = 0;
while (num > 0)
{
sum += num % 10;
num /= 10;
}
Console.WriteLine("Sum of digits: " + sum);
Console.ReadLine();
}
}
}
✅ 9. Count Vowels in a String
using System;
namespace VowelCount
{
class Program
{
static void Main(string[] args)
{
string input = "interview";
int count = 0;
foreach (char c in input.ToLower())
{
if ("aeiou".Contains(c))
{
count++;
}
}
Console.WriteLine("Number of vowels: " + count);
Console.ReadLine();
}
}
}
✅ 10. Multiplication Table
using System;
namespace MultiplicationTable
{
class Program
{
static void Main(string[] args)
{
int num = 5;
Console.WriteLine("Multiplication Table of " + num + ":");
for (int i = 1; i <= 10; i++)
{
Console.WriteLine($"{num} x {i} = {num * i}");
}
Console.ReadLine();
}
}
}
✅ 1. Swap Two Numbers (Using Extra Variable)
OUTPUT
After swapping:
x = 20
y = 10
C# Programs for Interview
using System;
namespace SwappingWithoutTemp
{
class Program
{
static void Main(string[] args)
{
int a = 5, b = 10;
a = a + b;
b = a - b;
a = a - b;
Console.WriteLine("After swapping:");
Console.WriteLine("a = " + a);
Console.WriteLine("b = " + b);
Console.ReadLine();
}
}
}
OUTPUT
Reversed string: olleh
OUTPUT
Palindrome
OUTPUT
Fibonacci Series:
0 1 1 2 3 5 8 13 21 34
OUTPUT
Factorial of 5 is: 120
OUTPUT
17 is Prime
OUTPUT
Sum of digits: 6
OUTPUT
Number of vowels: 4
OUTPUT
Multiplication Table of 5:
5 x 1 = 5
5 x 2 = 10
5 x 3 = 15
5 x 4 = 20
5 x 5 = 25
5 x 6 = 30
5 x 7 = 35
5 x 8 = 40
5 x 9 = 45
5 x 10 = 50